Depression No Longer Linked to Seratonin

Hey you guys. I don't know who needs to hear this, but don't cut your ear off. This week a review that includes 17 studies since 2010 verified what many mental health professionals have known for decades – that the connection between depression and a chemical imbalance is unfounded. It is often treated as a fact that depression is related to serotonin levels. The review published this week shows not only a low correlation between serotonin levels and depression but that there is no connection. This is a game changer for the entire class of SSRI anti-depressants like Prozac. In the middle of a cultural shift popularizing increased mental health care (for example the new 988 crisis hotline), it’s concerning that the review also found more than 80% of the public believed the chemical imbalance theory to be absolutely true, while the industry has been more ambiguous. A lot of people have taken antidepressants under the implication that they had a chemical imbalance that the drug was going to correct. Even if a psychiatrist doesn’t explain to a patient that their prescription is for a serotonin imbalance, many will likely make that assumption due to decades of pharmaceutical marketing and “doctor approved” public messages.

Now with telehealth, it takes a 30 minute zoom call to get Prozac. While a lot of people are prescribed SSRIs, there’s never been a standardized medical test in place to assess if the patient actually has a problem with irregular serotonin levels. Industry skeptics of the chemical imbalance theory have been muffled and discounted for decades. For example, one 2005 paper titled, “Serotonin and Depression: A Disconnect Between the Advertisements and Scientific Literature” puts forth that more than leaning on studies, supporters of the chemical imbalance theory leaned on the vagueness that because SSRI’s have an effect, the chemical imbalance theory must be right. It counters that, “The fact that aspirin cures headaches does not prove that headaches are due to low levels of aspirin in the brain.” People taking SSRIs make up 13% of Americans and 18% of American women. It’s a $15 billion-dollar industry that’s projected to reach $21 billion in the next ten years.

This isn’t about whether depression is absolutely real and very important – but it's about the fact that the public has been marketed towards a specific, false, narrative about depression to sell drugs. There is not a debate around whether SSRIs “do something”; they definitely do something. But the effect is not from “rebalancing” serotonin. At this time, it is unclear how or why SSRIs are often effective. Depression is a complex issue and the onset of depression can be acute or chronic, with different markers for each individual. It is not like prescribing insulin for diabetes. Our cultural desire to “medically” explain depression with an over-simplified chemical imbalance theory speaks to our want to find easy solutions for things that there isn’t a clear understanding of. In response to these findings, Psychology Today published a piece offering alternative theories to explore now that we can rule out the chemical imbalance theory. Things like a new understanding of neuroplasticity (the brain's ability to re-wire itself based on changing circumstances), inflammation in the bloodstream caused by poor diet and lack of sleep, and examining the brain-gut axis are new directions to consider.